Armature for rotating electric machine

ABSTRACT

In an armature, a coil includes a plurality of conductor segments, each provided with a conducting side section and a pair of protruding sections. The two protruding sections in each pair extend in opposite directions from each other with respect to a circumferential direction. Each protruding section is joined to a protruding section of another conductor segment to which that conductor segment is joined. At least one of each two protruding sections joined to each other is provided with an offset bend section that offsets a tip towards the other protruding section in a radial direction. The join surfaces formed on the tips of the two protruding sections are joined facing each other in the circumferential direction.

INCORPORATION BY REFERENCE

The disclosure of Japanese Patent Application No. 2010-033943 filed on Feb. 18, 2010 including the specification, drawings and abstract is incorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The present invention relates to armatures for rotating electrical machines, which include an armature core in which a plurality of slots extending in an axial direction of a cylindrical core reference plane are arranged so as to be distributed in a circumferential direction of the core reference plane, and a coil that is wound about the armature core.

DESCRIPTION OF THE RELATED ART

In order to increase the ratio of the area that is occupied by a coil in armatures for rotating electrical machines, a technique is already known in the art in which conductor side portions of a plurality of segment conductors are regularly arranged in slots of an armature core, and protruding portions of the different segment conductors, which protrude beyond the armature core in the axial direction, are joined together to form a coil (see, e.g., Japanese Patent No. 3196738 (FIG. 7, etc.)). In the structure described in Japanese Patent No. 3196738 (FIG. 7, etc.), as shown in FIG. 7 of the document, joint faces are formed in respective tip ends of the two protruding portions to be joined together, and joined together so as to face each other in a radial direction. Thus, in the structure of Japanese Patent No. 3196738 (FIG. 7, etc.), the size of the joints formed by joining the joint faces together is increased in the radial direction. Thus, the distance between the joints located adjacent to each other in the radial direction tends to be short, making it difficult to ensure an electric insulating property between the multiplicity of joints located outside the armature core in the radial direction.

Regarding such a problem of the electric insulating property between the joints, Japanese Patent Application Publication No. JP-A-2000-166150 below describes a structure in which the ratio of the length between a pair of protruding portions that are joined at a joint is not 1, and the ratio is varied between the joints located adjacent to each other in the radial direction. Japanese Patent Application Publication No. JP-A-2000-166150 describes that with such a structure, the adjacent joints do not overlap each other as viewed in the radial direction, and the distance between the adjacent joints can be secured.

However, in the structure described in Japanese Patent Application Publication No. JP-A-2000-166150, the pair of protruding portions included in the segment conductor have different lengths from each other, and a plurality of types of such segment conductors need to be used. This requires strict control of the orientation and types of the segment conductors when manufacturing the armatures for rotating electrical machines, which may increase the manufacturing cost.

SUMMARY OF THE INVENTION

It is therefore desired to implement an armature for a rotating electrical machine, which easily ensures an electric insulating property between joints that are adjacent to each other in the radial direction, while suppressing an increase in manufacturing cost.

An armature for a rotating electrical machine according to a first aspect of the present invention includes: an armature core in which a plurality of slots extending in an axial direction of a cylindrical core reference plane are arranged so as to be distributed in a circumferential direction of the core reference plane; and a coil that is wound about the armature core. The armature has a characteristic structure in which the coil is formed by using a plurality of segment conductors each including a conductor side portion placed in the slot, and a pair of protruding portions extending from the conductor side portion to protrude beyond the armature core to both sides in the axial direction, and tilted in the circumferential direction with respect to an extending direction of the conductor side portion so as to be located gradually away from the armature core in the axial direction, extending directions of the pair of protruding portions in the circumferential direction are opposite from each other, each of the protruding portions is joined to the protruding portion of another one of the segment conductors, which is a joint segment conductor to be joined to the each protruding portion, at least one of the two protruding portions to be joined together has a offset bent portion that offsets a tip end toward the other of the protruding portions in a radial direction of the core reference plane, and joint faces formed in the tip ends of the two protruding portions are joined together so as to face each other in the circumferential direction.

In the present application, the “rotating electrical machine” is used as a concept including all of a motor (an electric motor), a generator (an electric generator), and a motor-generator that functions both as the motor and the generator as necessary.

According to the first aspect, the tip ends of the two protruding portions to be joined together are arranged next to each other in the circumferential direction of the core reference plane. Thus, the size of a joint formed by joining the joint faces together can be reduced in the radial direction as compared to the structure in which the joint faces are joined together so as to face each other in the radial direction. Thus, even if the number of conductor side portions to be placed in each slot is increased, and the plurality of joints are arranged next to each other in the radial direction, the distance between the plurality of joints can be easily appropriately secured, whereby an electric insulating property between the joints, and an electric insulating property of the entire coil can be easily ensured.

Note that such electric insulating properties can be ensured without varying the ratio of the length between the two protruding portions to be joined together at the joint, between the joints that are adjacent to each other in the radial direction. That is, in the present invention, the ratio of the length between the two protruding portions to be joined together at the joint need not necessarily be varied between the joints that are adjacent to each other in the radial direction. For example, the joints that are adjacent to each other in the radial direction may have the same ratio of the length between the two protruding portions.

As described above, according to the first aspect, the plurality of segment conductors can be easily made to have the same shape, and the electric insulating property between the joints that are adjacent to each other in the radial direction can be easily ensured while suppressing an increase in manufacturing cost.

According to a second aspect of the present invention, an adjacent same-layer segment conductor for each of the segment conductors may be another one of the segment conductors whose conductor side portion is placed in a same position in the radial direction in an adjacent one of the slots, and the offset bent portion may be provided in a gap in the circumferential direction between the tip end of the protruding portion to be joined that is included in the joint segment conductor, and the tip end of the protruding portion included in the adjacent same-layer segment conductor for the joint segment conductor.

According to the second aspect, the offset bent portion that offsets the tip end can be appropriately provided in the protruding portion in a region other than the tip ends of the protruding portions of the segment conductors (including the adjacent same-layer segment conductor of the joint segment conductor) other than the joint segment conductor. Thus, even if the protruding portions of the other segment conductors are placed at the same position in the radial direction as the protruding portion to be joined, the tip end can be placed so that the joint face faces, in the circumferential direction, the joint face to be joined without causing interference between the segment conductors.

According to a third aspect of the present invention, the protruding portions of each of the segment conductors may be respectively placed adjacent to the protruding portions of the adjacent same-layer segment conductor so as to be arranged parallel to the protruding portions of the adjacent same-layer segment conductor, and arranged next to each other at a same position in the radial direction as the protruding portions of the adjacent same-layer segment conductor.

Note that as used herein, the expression “arranged next to each other at the same position in the radial direction” refers to the state in which the protruding portions are arranged at the same position in the radial direction in the core reference plane, but the positions of the protruding portions are sequentially shifted in the circumferential direction.

According to the third aspect, the protruding portions of each of the segment conductors are respectively placed adjacent to the protruding portions of the adjacent same-layer segment conductor so as to be arranged parallel to the protruding portions of the adjacent same-layer segment conductor, and arranged next to each other at a same position in the radial direction as the protruding portions of the adjacent same-layer segment conductor. Thus, the protruding portions of the plurality of segment conductors can be placed at a high density without performing processing, etc. on the protruding portions. This can suppress an increase in size in the radial and axial directions of the portions (coil end portions) of the coil protruding beyond the armature core in the axial direction, thereby facilitating reduction in size of the armature for the rotating electrical machine.

According to a fourth aspect of the present invention, the joint segment conductor for each of the segment conductors may be another one of the segment conductors whose conductor side portion is placed at a position in the radial direction adjacent to the conductor side portion of the segment conductor in the one of slots different from the slot in which the each segment conductor is placed.

According to the fourth aspect, the offset amount of the offset bent portion can be reduced, whereby the structure of the offset bent portion can be simplified. This can suppress an increase in manufacturing cost and an increase in size of the coil resulting from providing the offset bending portion.

According to a fifth aspect of the present invention, the armature may further include a plurality of radial arrangement portions in which a plurality of joints, each of which is formed between the joint faces of the two protruding portions, are arranged next to each other in the radial direction, and the plurality of joints forming each of the radial arrangement portions be arranged at uniform intervals in the radial direction.

According to the fifth aspect, for all of the joints that form the radial arrangement portion, the distance between each of the joints and the joint that is adjacent in the radial direction can be easily appropriately secured, whereby the overall electric insulating property of the coil can more easily be ensured.

According to a sixth aspect of the present invention, the slots may have an opening on one side in the radial direction of the core reference plane, and a width of the opening in the circumferential direction may be set to such a width that allows the conductor side portion to be inserted in the radial direction.

According to the sixth aspect, the segment conductor can be inserted into the slot of the armature core along the radial direction from the opening side. Thus, the segment conductor, in which the pair of protruding portions whose extending directions in the circumferential direction are opposite from each other are formed on both sides in the axial direction, can be appropriately inserted into the slot. Thus, the plurality of segment conductors can be joined together without performing processing, such as bending, on the segment conductors after the segment conductors are inserted into the slots. This simplifies the manufacturing process, whereby the matching cost can be reduced.

According to a seventh aspect of the present invention, the tip end of each of the protruding portions may be formed at a same position in the radial direction as the tip end of a joint protruding portion, which is the protruding portion to be joined to the each protruding portion, so as to extend parallel to an extending direction of the tip end of the joint protruding portion.

According to the seventh aspect, the tip ends of the two protruding portions to be joined together can be placed parallel to each other, and can be arranged next to each other in the circumferential direction at the same position in the radial direction. Thus, the segment conductors can be easily and reliably joined together.

According to an eighth aspect of the present invention, each of the protruding portions may include a main body portion that extends in the circumferential direction, and is formed in a linear shape extending in a direction tilted with respect to the extending direction of the conductor side portion as the core reference plane is viewed in the radial direction and in an arc shape parallel to the core reference plane as the core reference plane is viewed in the axial direction.

According to the eighth aspect, the main body portions of the protruding portions are arranged in a cylindrical shape that matches the shape of the armature core. Thus, the protruding portions of the plurality of segment conductors can be placed at a high density in a shape that matches the shape of the armature core, without performing processing, etc. on the protruding portions. This can suppress an increase in size in the radial and axial directions of the coil end portions protruding beyond the armature core in the axial direction, thereby facilitating reduction in size of the armature for the rotating electrical machine.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a wave winding coil portion according to an embodiment of the present invention;

FIG. 2 is a perspective view of a segment conductor according to the embodiment of the present invention;

FIG. 3 is a perspective view of a wave winding coil set according to the embodiment of the present invention;

FIG. 4 is a perspective view of a stator according to the embodiment of the present invention;

FIG. 5 is a partial enlarged view of the stator according to the embodiment of the present invention as viewed from an axial first direction side;

FIGS. 6A and 6B show enlarged schematic views of a portion near a joint of a coil according to the embodiment of the present invention;

FIG. 7 is a perspective view illustrating a method of inserting the segment conductor into a stator core according to the embodiment of the present invention;

FIGS. 8A and 8B show enlarged schematic views of a portion near a joint of a coil according to another embodiment of the present invention;

FIGS. 9A and 9B show enlarged schematic views of a portion near a joint of a coil according to another embodiment of the present invention;

FIGS. 10A and 10B show enlarged schematic views of a portion near a joint of a coil according to another embodiment of the present invention;

FIGS. 11A and 11B show enlarged schematic views of a portion near a joint of a coil according to another embodiment of the present invention.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An embodiment of an armature for a rotating electrical machine according to the present invention will be described below with reference to the accompanying drawings. The present embodiment is described with respect to an example in which the armature for the rotating electrical machine according to the present invention is applied to a stator 1 (see FIG. 4) of an inner rotor type rotating electrical machine. A coil 4 included in the stator 1 is formed by using a plurality of segment conductors 5 (see FIG. 2) each having a pair of protruding portions 7 whose extending directions in a circumferential direction C are opposite from each other. In such a structure, as shown in FIGS. 6A and 6B, the stator 1 of the present embodiment is characterized in that joint faces 60 formed in the segment conductors 5 are joined together at a joint 61 between the segment conductors 5 so as to face each other in the circumferential direction C. This makes it easier to ensure an electrical insulation property between the joints 61 located adjacent to each other in a radial direction R, while suppressing an increase in manufacturing cost. The structure of the stator 1 of the present embodiment will be described below in the order of “Overall Structure of Stator,” “Structure of Segment Conductors,” and “Structure of Coil.” In the present embodiment, the stator 1 and a stator core 2 correspond to an “armature for a rotating electrical machine” and an “armature core” in the present invention, respectively.

In the following description, an “axial direction L,” the “circumferential direction C,” and the “radial direction R” are defined based on the central axis of a cylindrical core reference plane S (see FIGS. 4 and 5) described above, unless otherwise specified. An “axial first direction L1” refers to an upward direction along the axial direction L in FIG. 4, and an “axial second direction L2” refers to a downward direction along the axial direction L in FIG. 4. As shown in FIG. 4, a “circumferential first direction C1” refers to a clockwise direction as the stator 1 is viewed from the axial first direction L1 side (as the axial second direction L2 side is viewed from the axial first direction L1 side), and a “circumferential second direction C2” refers to a counterclockwise direction as the stator 1 is viewed from the axial first direction L1 side. A “radial inward direction R1” refers to a direction toward the inside of the core reference plane S in the radial direction R, and a “radial outward direction R2” refers to a direction toward the outside of the core reference plane S in the radial direction R.

In the following description, the directions regarding the coil 4 and the segment conductors 5 forming the coil 4 are defined as directions in the state in which the coil 4 and the segment conductors 5 are mounted on the stator core 2. Note that in the specification, the directions of the members, and the relation of the directions in which two members are arranged (e.g. “parallel,” “perpendicular,” etc.) are used as concepts including displacements according to manufacturing errors. Such manufacturing errors are caused by, e.g., a displacement within a tolerance of the dimensions or the attachment positions.

1. Overall Structure of Stator

The overall structure of the stator 1 according to the present embodiment will be described below. FIG. 1 is a wave winding coil portion 8 that forms the coil 4 included in the stator 1. In order to facilitate understanding of the invention, first layer segment conductors 5 a described later are shown hatched, and second layer segment conductors 5 b are shown more lightly hatched than the first layer segment conductors 5 a. This wave winding coil portion 8 is formed by using a plurality of such segment conductors 5 as shown in FIG. 2, and a wave winding coil of five turns corresponding to five windings (five rounds) about the stator core 2 (see FIG. 4) is formed as the entire wave winding coil portion 8.

As shown in FIG. 3, a wave winding coil set 9 is formed by two wave winding coil portions 8 whose conductor side portions 31 are inserted into the same slots 3. As shown in FIG. 4, the coil 4 is fowled by six wave winding coil sets 9 arranged so as to be shifted from each other by one slot pitch in the circumferential direction C. Thus, the coil 4 is wound in a wave pattern about the stator core 2 included in the stator 1.

The stator core 2 is made of a magnetic material, and as shown in FIG. 4, is formed in a cylindrical shape as a whole except attachment protruding portions 33 for attachment to a case, etc. An attachment hole 33 a is formed in each attachment protruding portion 33 so as to extend therethrough in the axial direction L. The stator core 2 is formed by distributing the plurality of (48 in this example) slots 3, extending in the axial direction L, in the circumferential direction C so as to allow the coil 4 to be wound thereabout. The plurality of slots 3 are arranged at fixed intervals (slot pitches) in the circumferential direction C, and are provided to extend at least in the axial direction L.

In the present embodiment, the slots 3 are formed in a groove shape extending in the axial direction L and the radial direction R, and having a fixed width in the circumferential direction C. Each slot 3 has an opening 3 a on one side in the radial direction R (in this example, the radial inward direction R1 side), and has openings on both sides in the axial direction L of the stator core 2. That is, each slot 3 is formed to open to the inner peripheral surface of the core and to open to both sides in the axial direction L (both end faces in the axial direction) of the stator core 2. Thus, the plurality of slots 3 are formed in the stator core 2 so as to extend in a radial pattern in the radial direction R from the central axis of the stator core 2. The plurality of slots 3 have the same shape.

Although detailed description is omitted, in this example, the stator 1 is a stator that is used in a rotating electrical machine that is driven by a three-phase alternating current, and the slots 3 or sets of the slots 3 (e.g., sets each formed by two slots 2) corresponding to the three phases are arranged to repeatedly appear along the circumferential direction C. The coil 4 is formed by phase coils corresponding to each phase.

The cylindrical core reference plane S used as a reference of the axial direction L, the circumferential direction C, and the radial direction R is an imaginary plane that is used as a reference for the arrangement and structure of the slots 3. In the present embodiment, as shown in FIGS. 4 and 5, a core inner peripheral plane can be defined which is an imaginary cylindrical plane including the end faces on the radial inward direction R1 side of teeth 32 located between the slots 3 that are adjacent to each other in the circumferential direction C. This cylindrical core inner peripheral plane can be used as the “cylindrical core reference plane S” in the present invention. A cylindrical plane (including an imaginary plane) which is concentric with the cylindrical core inner peripheral plane, and whose cross-sectional shape as viewed in the axial direction L (as viewed along the axial direction L) is similar to the cross-sectional shape of this core inner peripheral plane as viewed in the axial direction L can also be used as the “cylindrical core reference plane S” in the present invention. For example, the outer peripheral surface of the stator core 2 except the attachment protruding portions 33 can be used as the “cylindrical core reference plane S.”

N (where N is an integer of 2 or more, and an even number is especially desirable) conductor side portions 31 are arranged in line so as to be positioned next to each other at the same position in the circumferential direction C. In the present embodiment, N is “10,” and the coil 4 is a 10-layer winding structure. In the specification, the respective positions in the radial direction R of the plurality of conductor side portions 31 arranged in the radial direction R in each slot 3 are represented by layers. Specifically, regarding the positions of the conductor side portions 31 in each slot 3, the outermost position on the radial outward direction R2 side is referred to as a first layer, and the other positions are sequentially referred to as a second layer, a third layer, . . . , and a tenth layer toward the radial inward direction R1 side. Thus, each conductor side portion 31 is placed in any one of the first layer to the N^(th) layer (the tenth layer in this example) that are set sequentially adjacent to each other from the radial outward direction R2 side toward the radial inward direction R1 side in each slot 3.

Although not shown in the drawings, a rotor as a field magnet including a permanent magnet or an electromagnet is placed on the radial inward direction R1 side of the stator 1 (the stator core 2) so as to be rotatable relative to the stator 1. The rotor is rotated by a rotating magnetic field that is generated from the stator 1. Thus, the stator 1 of the present embodiment is a stator as an armature for an inner rotor type, rotating field type rotating electrical machine. In other words, the stator 1 is placed to face the rotor as the field magnet in the radial direction R, and together with the rotor, forms a rotating electrical machine.

2. Structure of Segment Conductors

The structure of the segment conductors 5 that form the coil 4 will be described below. Note that in the following description, regarding each segment conductor 5, other segment conductors 5 to be joined thereto are referred to as “joint segment conductors,” and the protruding portions 7 to be joined, which are included in each joint segment conductor, are referred to as “joint protruding portions.” Moreover, regarding each segment conductor 5, other segment conductors 5 whose conductor side portions 31 are placed in the same position in the radial direction R (the same layer) as that of the segment conductor 5 in adjacent slots 3 are referred to as “adjacent same-layer segment conductors.” Note that although the coil 4 of the present embodiment includes irregularly shaped segment conductors having a different shape from the segment conductors 5 described below, as segment conductors that form ends connected to a power source or a neutral point, or connection portions between the turns, description of the irregularly shaped segment conductors will be omitted.

The segment conductors 5 are conductors corresponding to a plurality of divided segments of the coil 4 (the phase coils of each phase), and the coil 4 that encircles the stator core 2 is formed by joining the ends (tip ends 71 described below) of the plurality of segment conductors 5. In the present embodiment, as shown in FIGS. 2 and 5, each segment conductor 5 is formed by a rectangular linear conductor whose cross section perpendicular to an extending direction of the segment conductor 5 (which is the same as a current carrying direction) has a rectangular shape, and more specifically, has arc-shaped corners. The segment conductors 5 basically have the same cross-sectional shape regardless of the position in the extending direction of the segment conductor 5, except bent portions (first circumferential bent portions 11, second circumferential bent portions 12, and offset bent portions 13) described below. A material that forms the linear conductors can be, e.g., copper, aluminum, etc. The surface of each linear conductor is coated with an insulating coating of a resin, etc. (e.g., polyimide, etc.) except a part of the surface, such as the joint faces 60 that are portions to be electrically connected to the joint segment conductors.

As shown in FIG. 2, each segment conductor 5 includes the conductor side portion 31 placed in the slot 3, and the pair of protruding portions 7 extending from the conductor side portion 31 and protruding beyond the stator core 2 on both sides in the axial direction L. The conductor side portion 31 is a portion of the segment conductor 5 which is inserted into the slot 3 of the stator core 2, and is shaped to match the shape of the slot 3. In this example, the conductor side portion 31 is formed in a linear shape extending parallel to the axial direction L. The conductor side portion 31 is placed in the slot 3 so that the shorter side of the rectangular cross section perpendicular to the extending direction of the linear conductor is parallel to the radial direction R, and the longer side thereof is parallel to the circumferential direction C.

In the following description, in the case where the individual segment conductor 5 is mentioned based on the layer in the slot 3 in which the conductor side portion 31 is placed, the segment conductor 5 is referred to as the “M^(th) layer segment conductor,” where M represents the number of the layer (in this example, M is an integer of 1 to 10). That is, in this example, as shown in FIG. 1, a first layer segment conductor 5 a, a second layer segment conductor 5 b, a third layer segment conductor 5 c, a fourth layer segment conductor 5 d, a fifth layer segment conductor 5 e, a sixth layer segment conductor 5 f, a seventh layer segment conductor 5 g, an eighth layer segment conductor 5 h, a ninth layer segment conductor 5 i, and a tenth layer segment conductor 5 j are provided as the segment conductors 5.

Each of the pair of protruding portions 7 is formed to be tilted in the circumferential direction C with respect to the axial direction L that is the extending direction of the conductor side portion 31, so as to be gradually located away from the stator core 2 in the axial direction L. The extending directions of the pair of protruding portions 7 in the circumferential direction C are opposite from each other. Specifically, in the case where the extending directions of the pair of protruding portions 7 in the circumferential direction C are directions away from the conductor side portion 31, as shown in FIG. 1, the extending direction of the protruding portion 7 on the axial first direction L1 side in the circumferential direction C is a circumferential second direction C2, and the extending direction of the protruding portion 7 on the axial second direction L2 side in the circumferential direction C is a circumferential first direction C1, regarding the odd-numbered-layer segment conductors (e.g., the first layer segment conductor 5 a) whose conductor side portions 31 are placed in the odd-numbered layers. Regarding the even-numbered-layer segment conductors (e.g., the second layer segment conductor 5 b) whose conductor side portions 31 are placed in the even-numbered layers, the extending direction of the protruding portion 7 on the axial first direction L1 side in the circumferential direction C is the circumferential first direction C1, and the extending direction of the protruding portion 7 on the axial second direction L2 side in the circumferential direction C is the circumferential second direction C2.

The structure of the protruding portions 7 will be described in more detail below. As shown in FIG. 2, each protruding portion 7 includes the first circumferential bent portion 11, the second circumferential bent portion 12, a main body portion 73 forming a part between the first circumferential bent portion 11 and the second circumferential bent portion 12 and extending in the circumferential direction C, and the offset bent portion 13. The first circumferential bent portion 11 is a bent portion for tilting the extending direction of the main body portion 73 in the circumferential direction C with respect to the extending direction of the conductor side portion 31. The tilt angle of the extending direction of the main body portion 73 is determined according to the bend angle of the first circumferential bent portion 11. Note that as described above, the extending directions of the pair of protruding portions 7 included in the segment conductor 5 in the circumferential direction C are opposite from each other. Thus, the first circumferential bent portion 11 on the axial first direction L1 side and the first circumferential bent portion 11 on the axial second direction L2 side are bent in the opposite directions from each other. In the present embodiment, as shown FIGS. 2 and 5, the main body portion 73 is formed in a linear shape extending in a direction tilted with respect to the extending direction of the conductor side portion 31 as viewed in the radial direction R, and is formed in an arc shape parallel to the core reference plane S as viewed in the axial direction L.

If the bend angle of the first circumferential bent portion 11 is defined based on the direction (0 degrees) extending away from the stator core 2 and parallel to the extending direction of the conductor side portion 31 (the axial direction L), the bend angle of the first circumferential bent portion 11 is set to an acute angle. Thus, the main body portion 73 is formed to be located gradually away from the stator core 2 in the axial direction L. In other words, the main body portion 73 is formed to extend toward one side in the circumferential direction C as the main body portion 73 is located away from the stator core 2 in the axial direction L.

The second circumferential bent portion 12 is a bent portion for tilting the extending direction of the tip end 71 of the protruding portion 7 with respect to the extending direction of the main body portion 73, as viewed in the radial direction R. In this example, the second circumferential bent portion 12 is formed so that the extending direction of the tip end 71 is parallel to the axial direction L. The protruding portion 7 is joined to the protruding portion 7 of the joint segment conductor by joining the tip end 71 of the former protruding portion 7 to the tip end 71 of the joint protruding portion. The tip end 71 is a portion including an edge of the protruding portion 7, which is located on the opposite side from the conductor side portion 31 from which the protruding portion 7 extends. In this example, a portion from the offset bent portion 13 to this edge forms the tip end 71. That is, in this example, the tip end 71 is a portion which includes this edge, and in which the extending direction is the same. The face of the tip end 71 which faces the tip end 71 of the joint protruding portion serves as the joint face 60 that is joined to the joint protruding portion. In this example, the face of the tip end 71 which faces the opposite side from the conductor side portion 31 of the segment conductor 5 provided with the tip end 71 in the circumferential direction C serves as the joint face 60. Thus, the tip end 71 is a portion of the protruding portion 7 where the joint face 60 is formed.

The offset bent portion 13 is a bent portion that offsets the tip end 71 of the protruding portion 7 toward the joint protruding portion 7 (to be exact, the tip end 71 to be joined) in the radial direction R. In this example, the offset bent portion 13 is a bent portion that offsets the tip end 71 in the radial direction R with respect to the portion (the main body portion 73) on the conductor side portion 31 side in the protruding portion 7, so that the tip end 71 is located at the same position in the radial direction R as the joint protruding portion 7 (the tip end 71). As shown in FIGS. 6A and 6B, the offset bent portion 13 is formed in a crank shape (in this example, a crank shape having an obtuse bend angle) as viewed in the circumferential direction C. In the present embodiment, the offset bent portion 13 is formed in both of the pair of protruding portions 7 of the segment conductor 5, and the offset amount d of each offset bent portion 13 in the radial direction R is half the thickness in the radial direction R of the linear conductor in the conductor side portion 31 (corresponding to half the layer) (see FIG. 6B). Thus, in the present embodiment, the coil 4 formed by the segment conductors 5 has the joints 61 on both sides in the axial direction L, and is formed similarly on both the axial first direction L1 side and the axial second direction L2 side. In this example, the offset bent portion 13 is provided at a position adjacent to the second circumferential bent portion 12 on the tip end 71 side.

The length of the protruding portion 7 in the circumferential direction C is basically set according to the distance by which the conductor side portion 31 from which the protruding portion 7 extends is separated in the circumferential direction C from the conductor side portion 31 of the joint segment conductor. The extending length of each member in the circumferential direction C is the length in the circumferential direction C when the member is projected onto a plane perpendicular to the axial direction L. In this example, this distance is set to a value corresponding to 6 slot pitches, and the length of the protruding portion 7 in the circumferential direction C is set to approximately half this value (corresponding to about 3 slot pitches).

3. Structure of Coil

The structure of the coil 4 formed by the segment conductors 5 described above will be described below. As described above, the coil 4 includes a plurality of the wave winding coil portions 8 as shown in FIG. 1. As shown in FIG. 1, each wave winding coil portion 8 is formed by sequentially joining the protruding portions 7 of each pair of segment conductors 5 whose conductor side portions 31 are placed in adjacent layers in the different slots 3, alternately on one side and the other side in the axial direction L toward the circumferential first direction C1 side. Specifically, each wave winding coil portion 8 is formed by sequentially joining each odd-numbered-layer segment conductor and each even-numbered-layer segment conductor, which are placed in adjacent layers and whose conductor side portions 31 are placed in the slots 3 that are separated from each other by one magnetic pole pitch (in this example, 6 slot pitches), toward the circumferential first direction C1 side.

The structure of the wave winding coil portion 8 will be described in more detail below. As shown in FIG. 1, a coil of one turn corresponding to one winding (one round) about the stator core 2 is formed by alternately joining four odd-numbered-layer segment conductors (e.g., the first layer segment conductor 5 a) and four even-numbered-layer segment conductors (e.g., the second-layer segment conductor 5 b) on both sides in the axial direction L so as to encircle (form one complete turn about) the stator core 2 in the circumferential direction C. In the entire wave winding coil portion 8, a coil of five turns is formed by 20 odd-numbered-layer segment conductors and 20-even-numbered-layer segment conductors. Thus, in the present embodiment, the joint segment conductor for each segment conductor 5 is another segment conductor 5 whose conductor side portion 31 is placed at a position in the radial direction R (a layer) adjacent to the conductor side portion 31 of the segment conductor 5 in the slot 3 different from the slot 3 where the segment conductor 5 is placed.

In the present embodiment, in basically all the segment conductors 5, the offset bent portion 13 that offsets the tip end 71 toward the joint protruding portion 7 in the radial direction R is formed in each of the pair of protruding portions 7. Thus, in this example, both of the two protruding portions 7 to be joined together include the offset bent portion 13. As described above, the offset amount d of each offset bent portion 13 is half the thickness in the radial direction R of the linear conductor (corresponding to half the layer). Thus, the joint faces 60 (see FIGS. 6A and 6B) formed at the tip ends 71 of the two protruding portions 7 to be joined together are placed to face each other in the circumferential direction C at the same position in the radial direction R. That is, the joint 61 formed by joining the two joint faces 60 together is formed by joining the joined faces 60 of the two protruding portions 7 to be joined together, so that the joint faces 60 face each other in the circumferential direction C. With such a structure, the joint 61 formed by the two tip ends 71 can be shaped to be smaller in the radial direction R than in the circumferential direction C, whereby the distance between joints 61 that are adjacent to each other in the radial direction is appropriately secured, and the electric insulating property between the joints 61 is easily ensured.

In the present embodiment, as shown in FIG. 2, the second circumferential bent portion 12 is formed to make the extending direction of the tip end 71 parallel to the axial direction L. As described above, in the present embodiment, the segment conductors 5 whose conductor side portions 31 are placed in adjacent layers are joined together, and the offset amount d of each offset bent portion 13 included in both of the two protruding portions 7 that are joined together is set to a value corresponding to half the layer. Thus, as shown in FIGS. 1 and 6, in the present embodiment, the tip end 71 of the protruding portion 7 is placed to extend parallel to the extending direction of the tip end 71 of the joint protruding portion at the same position in the radial direction R as the tip end 71 of the joint protruding portion. With such a structure, the segment conductors can be easily and reliably joined together.

Moreover, in the present embodiment, the length in the circumferential direction C of the protruding portion 7 is set to about 3 slot pitches, in basically all the segment conductors 5. That is, in the present embodiment, the ratio of the length between the two protruding portions 7 that are joined together at the joint 61 is “1.” Thus, as shown in FIGS. 1 and 4, a plurality of (four in this example) radial arrangement portions 62, in which the joints 61 are located at the same position in the axial direction L and the plurality of joints 61 are arranged next to each other in the radial direction R at the same position in the circumferential direction C, are formed on each of the axial first direction L1 side and the axial second direction L2 side with respect to the stator core 2. In the present embodiment, as shown in FIG. 5, the pluralities of joints 61 respectively forming the radial arrangement portions 62 are arranged at uniform intervals in the radial direction R. Such an arrangement structure is implemented by causing all of the plurality of joints 61 forming the single radial arrangement portion 62 to have the same positional relation in the radial direction R with respect to the conductor side portions 31 from which the two protruding portions 7 forming the joint 61 extend.

Specifically, in the present embodiment, such an arrangement structure as described above is implemented by setting the bending direction and the offset amount d of each offset bent portion 13 so that the position of the joint 61 in the radial direction R is located at the center of the range in the radial direction R (in this example, corresponding to two layers) that is occupied by the conductor side portion 31 from which the two protruding portions 7 forming the joint 61 extend. Thus, the distance to the adjacent joint 61 in the radial direction R can be appropriately secured for all the joints 61 that form the radial arrangement portion 62.

The wave winding coil set 9 as shown in FIG. 3 is formed by the two wave winding coil portions S whose conductor side portions 31 are inserted into the same slot 3. Note that the conductor side portions 31 of one of the wave winding coil portions 8 that form the single wave winding coil set 9 and the conductor side portions 31 of the other wave winding coil portion 8 are alternately arranged in the radial direction R in each slot 3, and the order in the radial direction R alternates at each of the slots 3 in which the conductor side portions 31 forming the wave winding coil set 9 are placed and that are adjacent to each other in the circumferential direction C (in this example, in each of the slots 3 that are separated from each other by 6 slot pitches).

As shown in FIG. 4, the coil 4 is formed by shifting the six wave winding coil sets 9 having the above structure from each other by one slot pitch in the circumferential direction C. As shown in FIG. 4, the protruding portions 7 of each segment conductor 5 are respectively placed adjacent to the protruding portions 7 of the adjacent segment conductor in the same layer so as to be arranged parallel to, and arranged next to each other at the same position in the radial direction R as, the protruding portions 7 of the adjacent segment conductor. Specifically, the protruding portions 7 of the plurality of segment conductors 5 whose conductor side portions 31 are placed in the same layer in the slots 3 are arranged adjacent to each other so that the main body portions 73 extend parallel to each other (that is, extend in the same direction) and are arranged next to each other at the same position in the radial direction R.

In the present embodiment, the main body portions 73 are formed in an arc shape that is parallel to the core reference plane S as viewed in the axial direction L.

Thus, the protruding portions 7 of the plurality of segment conductors 5 whose conductor side portions 31 are placed in the same layer in the slots 3 are arranged to form a cylindrical shape as a whole. The main body portions 73 of the two segment conductors 5 in the same layer whose conductor side portions 31 are placed in the slots 3 that are adjacent to each other are arranged to extend parallel to each other at the same position in the radial direction R, and are placed at the positions that are shifted from each other by one slot pitch in the circumferential direction C. Thus, these two main bodies 73 are arranged next to each other on a cylindrical plane, and are arranged to overlap and face each other in the axial direction L in a part of a region in the circumferential direction C where the two main bodies 73 are present, specifically, in a central region in the circumferential direction C except regions corresponding to one slot pitch at both ends on the circumferential first direction C1 side and the circumferential second direction C2 side.

As described above, each main body portion 73 is formed in an arc shape that is parallel to the core reference plane S as viewed in the axial direction L. Thus, each main body portion 73 can be placed without interfering with the protruding portions (the main body portions 73) of other segment conductors 5 located on both sides in the radial direction R. Specifically, as shown in FIG. 5, each main body portion 73 is placed along the cylindrical plane parallel to the core reference plane S so as to extend in the circumferential direction C through the same position in the radial direction R as the conductor side portion 31 of the segment conductor 5 including this main body portion 73. Thus, except the protruding portions 7 that are placed at the end on the radial inward direction R1 side and the end on the radial outward direction R2 side, the main body portion 73 is placed to extend in the cylindrical direction C with the main body portion 73 being sandwiched between the protruding portions 7 of other segment conductors 5, from both sides of the main body portion 73 on the radial outward direction R2 side and the radial inward direction R1 side.

Moreover, in the present embodiment, each offset bent portion 13 is provided in a gap in the circumferential direction C between the tip end 71 of the joint protruding portion 7 included in the joint segment conductor, and the tip end 71 of the protruding portion 7 included in the adjacent same-layer segment conductor that is located adjacent to and in the same layer as the joint segment conductor. In this regard, the positional relation of each part will be described with reference to FIG. 5.

In FIG. 5, “7A” represents the protruding portion 7 of the segment conductor 5 to be mentioned herein, “7B” represents the joint protruding portion to be joined to this protruding portion 7, and “7C” represents the protruding portion 7 of the adjacent same-layer segment conductor that is located adjacent to and in the same layer as the segment conductor 5 (the joint segment conductor) including the joint protruding portion 7B, and the protruding portions 7A, 7B, and 7C are shown hatched in the drawing. In the example shown in FIG. 5, the main body portion 73 of the protruding portion 7A of the segment conductor 5 that is mentioned herein extends from the conductor side portion 31 side toward the circumferential second direction C2 side. The offset bent portion 13 provided in the protruding portion 7A is formed to offset the tip end 71 toward the joint protruding portion 7B in the radial direction R (in the illustrated example, toward the radial inward direction R1 side) with respect to the main body portion 73. Thus, the tip end 71 of the protruding portion 7A and the tip end 71 of the joint protruding portion 7B are arranged next to each other in the circumferential direction C, and as shown also in FIGS. 6A and 6B, are joined together so that the joint faces 60 formed in these tip ends 71 face each other in the circumferential direction C, whereby the joint 61 between the protruding portion 7A and the protruding portion 7B is formed.

On the conductor side portion 31 side of the protruding portion 7A (in the illustrated example, on the circumferential first direction C1 side) with respect to the joint protruding portion 7B is provided the protruding portion 7C of the adjacent same-layer segment conductor which is located adjacent to and in the same layer as the segment conductor 5 (the joint segment conductor) including the joint protruding portion 7B, and whose conductor side portion 31 is placed at the same radial position in the slot 3 adjacent to that of the joint segment conductor. Thus, the offset bent portion 13 provided in the protruding portion 7A is provided in the gap in the circumferential direction C between the tip end 71 of the joint protruding portion 7B included in the joint segment conductor and the protruding portion 7C of the adjacent same-layer segment conductor that is located adjacent to and in the same layer as the joint segment conductor, and the protruding portion 7A is bent in the radial direction R (in the illustrated example, the radial inward direction R1) in this gap to offset the tip end 71 of the protruding portion 7A. Accordingly, the offset bent portion 13 and the tip end 71 are placed in the range of the length in the circumferential direction C corresponding to one slot pitch or less between the tip end 71 of the joint protruding portion 7B and the tip end 71 of the protruding portion 7C. Thus, the offset bent portion 13 can be provided that appropriately offsets the tip end 71 in the radial direction while avoiding the protruding portions 7 of the segment conductors 5 other than the joint segment conductor and the tip ends 71 of these protruding portions 7, and the tip ends 71 of the two protruding portions 7 that are joined together can be placed so that the joint faces 60 formed in the tip ends 71 face each other in the circumferential direction C.

With the above arrangement structure, in the stator 1 of the present embodiment, the protruding portions 7 of the plurality of segment conductors 5 can be placed at a high density while avoiding interference between the segment conductors 5, without performing processing, etc. on the protruding portions 7. This suppresses an increase in size in the radial direction R and the axial direction L of the coil end portions protruding beyond the stator core 2 in the axial direction L.

As described above, each slot 3 includes the opening 3 a on the radial inward direction R1 side. The width in the circumferential direction C of the opening 3 a is set to such a width that allows the conductor side portion 31 of the segment conductor 5 to be inserted therein in the radial direction R. Specifically, the width in the circumferential direction C of the opening 3 a is set to be larger (in this example, slightly larger) than the width in the circumferential direction C of the conductor side portion 31 of the segment conductor 5. Thus, as shown in FIG. 7, the segment conductor 5 can be inserted from the opening 3 a side of the stator core 2 into the slot 3 along the radial direction R, when manufacturing the stator 1.

That is, in the present embodiment, the segment conductors 5 having the bent portions (the first circumferential bent portions 11, the second circumferential bent portions 12, and the offset bent portions 13) formed in advance can be inserted from the radial inward direction R1 side into the slots 3. In this structure, the segment conductors 5 can be joined together without performing processing, such as bending, on the segment conductors 5 after the segment conductors 5 are inserted into the slots 3, and the insulating coating that coats the segment conductors 5 is not damaged by such processing. Moreover, since the segment conductors 5 need not be deformed when inserted into the slots 3, the insulating coating that coats the segment conductors 5 is not damaged when inserting the segment conductors 5 into the slots 3. Thus, in the case of performing the step of fixing an insulating coating material to the protruding portions 7 of the segment conductors 5 by powder coating, etc., this step can be performed before inserting the segment conductors 5 into the slots 3. Moreover, the segment conductors 5 forming each layer need not necessarily be simultaneously inserted into the slots 3 on a layer-by-layer basis, and the segment conductors 5 may be inserted one-by-one into the slots 3. Thus, the stator 1 of the present embodiment has a structure that is also advantageous in terms of manufacturability.

4. Other Embodiments

Lastly, other embodiments of the present invention will be described below. Note that features disclosed in each of the following embodiments may be applied not only to that embodiment, but also to another embodiment as long as no inconsistency arises.

(1) The above embodiment is described with respect to an example in which both of the offset amounts d of the offset bent portions 13 provided in the two protruding portions 7 that are joined together are half the thickness in the radial direction R of the linear conductor (corresponding to half the layer). However, embodiments of the present invention are not limited to this, and the offset amounts d of the offset bent portions 13 provided in the two protruding portions 7 that are joined together can be changed independently of each other as appropriate. In this case, it is preferable to match the sum of the offset amounts d of the two offset bent portions 13 with the thickness in the radial direction R of the linear conductor.

Note that in the case where the sum of the offset amounts d of the two offset bent portions 13 is set to differ from the thickness in the radial direction R of the linear conductor, each offset amount d needs to be set so that the tip end 71 of the protruding portion 7 at least partially overlaps the tip end 71 of the joint protruding portion as viewed in the circumferential direction C. The faces of the overlapping portions that face each other in the circumferential direction C serve as the joint faces 60. Thus, in the present invention, the tip end 71 of the protruding portion 7 need not necessarily be placed at the same position in the radial direction R as the tip end 71 of the joint protruding portion, and the position in the radial direction R can be changed as appropriate within such a range that the tip end 71 of the protruding portion 7 at least partially overlaps the tip end 71 of the joint protruding portion as viewed in the circumferential direction C. In the structure in which the tip end 71 of the protruding portion 7 is placed to partially overlap the tip end 71 of the joint protruding portion as viewed in the circumferential direction C, the two tip ends 71 to be joined together can each be structured to extend in a direction parallel to the axial direction L as viewed in the circumferential direction C, and can also be structured to be shifted from each other in the radial direction R.

As shown in FIGS. 5A and 8B, the offset bent portion 13 may be provided in only one of the two protruding portions 7 to be joined together, rather than in both of the two protruding portions 7. In the example of FIGS. 5A and 813, the offset amount d of the offset bent portion 13 provided in the one protruding portion 7 is set to the thickness in the radial direction R of the linear conductor (corresponding to one layer) (see FIG. 8B).

(2) The above embodiment is described with respect to an example in which the face of the tip end 71 of the protruding portion 7, which faces the side in the circumferential direction C opposite to the conductor side portion 31 of the segment conductor 5 provided with the tip end 71, serves as the joint face 60. However, embodiments of the present invention are not limited to this. As shown in FIGS. 9A and 9B, the face of the tip end 71 of the protruding portion 7, which faces the side of the conductor side portion 31 of the segment conductor 5 provided with the tip end 71 in the circumferential direction C, may serve as the joint face 60. In this structure, the two protruding portions 7 to be joined together are placed so as to cross each other as viewed in the radial direction R. Thus, these protruding portions 7 can be hooked together so that the joint faces 60 formed in the protruding portions 7 are positioned to face each other in the circumferential direction C. Like the above embodiment, in this structure as well, it is preferable to provide the offset bent portion 13 in the gap in the circumferential direction C between the tip end 71 of the joint protruding portion 7 included in the joint segment conductor, and the tip end 71 of the protruding portion 7 included in the adjacent same-layer segment conductor located adjacent to and in the same layer as the joint segment conductor.

In this structure as well, the offset amounts d of the offset bent portions 13 provided in the two protruding portions 7 to be joined together can be changed independently of each other as appropriate. Note that in the example of FIGS. 9A and 9B, like the above embodiment, both of the offset amounts d of the offset bent portions 13 provided in the two protruding portions 7 to be joined together are set to half the thickness in the radial direction R of the linear conductor (corresponding to half the layer) (see FIG. 9B). Moreover, as shown in FIGS. 10A and 10B, the offset bent portion 13 may be provided in only one of the two protruding portions 7 to be joined together, rather than in both of the two protruding portions 7. In the example shown in FIGS. 10A and 10B, the offset amount d of the offset bent portion 13 provided in the one protruding portion 7 is set to the thickness in the radial direction R of the linear conductor (corresponding to one layer) (see FIG. 10B).

(3) The above embodiment is described with respect to an example in which the offset bent portion 13 is provided at a position adjacent to the second circumferential bent portion 12 on the tip end 71 side. However, embodiments of the present invention are not limited to this. The offset bent portion 13 may be provided at the same position as the second circumferential bent portion 12, or may be provided at a position adjacent to the second circumferential bent portion 12 on the conductor side portion 31 side. In the latter case, it is preferable that the offset bent portion 13 be formed to have a crank shape (in this example, a crank shape having an obtuse bend angle) as viewed in the axial direction L.

(4) The above embodiment is described with respect to an example in which the offset bent portion 13 is formed in both of the pair of protruding portions 7 in basically all of the segment conductors 5. However, embodiments of the present invention are not limited to this. The offset bent portion 13 may be formed in one of the pair of protruding portions 7 in basically all of the segment conductors 5. In such a structure, each segment conductor 5 can be placed so that the protruding portion 7 having the offset bent portion 13 formed therein is located on the axial first direction L1 side with respect to the stator core 2. In the coil end portion on the axial first direction L1 side, like the above embodiment, the two protruding portions 7 to be joined together can be joined together so that the joint faces 60 formed in the tip ends 71 face each other in the circumferential direction C. In the coil end portion on the axial second direction L2 side, the two protruding portions 7 to be joined together can be joined together so that the joint faces formed in the tip ends 71 face each other in the radial direction R.

The segment conductors 5 in which the offset bent portion 13 is formed in both of the pair of protruding portions 7, and the segment conductors 5 in which the offset bent portion 13 is not formed in both of the pair of protruding portions 7 may be used, and the segment conductors 5 may be placed so that one of the two protruding portions 7 to be joined together is the protruding portion 7 having the offset bent portion 13.

(5) The above embodiment is described with respect to an example in which the joint segment conductor for each segment conductor 5 is another segment conductor 5 whose conductor side portion 31 is placed at a position in the radial direction R (a layer) adjacent to the conductor side portion 31 of the segment conductor 5 in a slot 3 different from the slot 3 in which the segment conductor 5 is placed. However, embodiments of the present invention are not limited to this. The joint segment conductor for at least one of the segment conductors 5 may be another segment conductor 5 whose conductor side portion 31 is placed at the same position in the radial direction R (the same layer) as the conductor side portion 31 of the segment conductor 5, or may be another segment conductor 5 whose conductor side portion 31 is placed in a layer that is different by at least two layers from the conductor side portion 31 of the segment conductor 5.

(6) The above embodiment is described with respect to an example in which the plurality of joints 61 forming each radial arrangement portion 62 are arranged at uniform intervals in the radial direction R. However, embodiments of the present invention are not limited to this. The plurality of joints 61 forming each radial arrangement portion 62 may be arranged at non-uniform intervals in the radial direction R.

(7) The above embodiment is described with respect to an example in which the extending direction of the tip end 71 is a direction parallel to the axial direction L. However, the extending direction of the tip end 71 may be a direction tilted in the circumferential direction C or the radial direction R with respect to the axial direction L.

(8) The above embodiment is described with respect to an example in which the tip end 71 of the protruding portion 7 is placed to extend parallel to the extending direction of the tip end 71 of the joint protruding portion. However, embodiments of the present invention are not limited to this. The extending direction of the tip end 71 of the protruding portion 7 may not be parallel to the extending direction of the tip end 71 of the joint protruding portion. For example, the extending direction of at least one of the two tip ends 71 to be joined together may be a direction tilted in the radial direction R with respect to the axial direction L as viewed in the circumferential direction C, and the two tip ends 71 may be placed to cross each other as viewed in the circumferential direction C. In such a structure, the two joint faces 60 facing each other in the circumferential direction C are formed in the portion where the two tip ends 71 cross each other as viewed in the circumferential direction C, and the joint 61 is formed by joining the two joint surfaces 60 together. Specifically, for example, as shown in FIGS. 11A and 11B, the offset bent portion 13 may be provided in both of the two protruding portions 7 to be joined together, and each offset bent portion 13 may have only one bent location. In the example of FIGS. 11A and 11B, both of the two tip ends 71 to be joined together are formed to extend in a direction tilted toward the other tip end 71 in the radial direction R with respect to the axial direction L as viewed in the circumferential direction C.

(9) The above embodiment is described with respect to an example in which the main body portion 73 of the protruding portion 7 is formed in an arc shape parallel to the core reference plane S as viewed in the axial direction L. However, embodiments of the present invention are not limited to this. For example, it is also one of preferred embodiments of the present invention that the main body portion 73 be shaped like a straight line being bent in the circumferential direction C at one or a plurality of positions as viewed in the axial direction L. In this case as well, it is preferable that the main body portion 73 be placed substantially along the core reference plane S, and it is also preferable that such a main body portion 73 be shaped so that the main body portion 73 can be placed so as not to interfere with the protruding portions 7 of the other segment conductors 5.

(10) The above embodiment is described with respect to an example in which the main body portion 73 of the protruding portion 7 is formed in a linear shape extending in a direction tilted with respect to the extending direction of the conductor side portion 31 as viewed in the radial direction R. However, embodiments of the present invention are not limited to this. For example, it is also one of preferred embodiments of the present invention that the main body portion 73 be formed in a curved shape that is curved as viewed in the radial direction R, or the main body portion 73 be shaped to be bent at one or a plurality of positions as viewed in the radial direction R. In this case as well, the main body portion 73 is placed adjacent to the protruding portion 7 of the adjacent same-layer segment conductor, so that the main body portion 73 extends parallel to the protruding portion 7 of the adjacent same-layer segment conductor and is arranged next to the protruding portion 7 of the adjacent same-layer segment conductor at the same position in the radial position. Thus, for example, it is preferable that the plurality of segment conductors 5 have a common shape, such as the ease where the plurality of segment conductors 5 placed in the same layer are formed in an arc shape curved with the same curvature.

(11) The above embodiment is described with respect to an example in which the width in the circumferential direction C of the opening 3 a of the slot 3 is set to such a width that allows the conductor side portion 31 of the segment conductor 5 to be inserted in the radial direction R. However, embodiments of the present invention are not limited to this. The width in the circumferential direction C of the opening 3 a may be set smaller than the portion on the radial outward direction R2 side of the opening 3 a. In this structure, the segment conductor 5 in which at least one of the pair of protruding portions 7 is formed in a linear shape as viewed in the radial direction R can be first inserted into the slot 3 in the axial direction L, and then a necessary bent portion can be formed.

(12) The above embodiment is described with respect to an example in which the cross section of the linear conductor that forms the segment conductor 5, which is perpendicular to the extending direction of the linear conductor, has a rectangular shape. However, embodiments of the present invention are not limited to this. The cross section of the linear conductor may have a circular shape, an elliptical shape, a polygonal shape other than the rectangular shape, etc.

(13) The above embodiments are described with respect to an example in which the armature for the rotating electrical machine according to the present invention is applied to a stator for an inner rotor type rotating electrical machine. However, the armature for the rotating electrical machine according to the present invention may also be applied to a stator for an outer rotor type rotating electrical machine. The armature for the rotating electrical machine according to the present invention may also be applied to a rotor for a fixed field type rotating electrical machine.

(14) Regarding other structures as well, the embodiments disclosed in the specification are by way of example only in all respects, and embodiments of the present invention are not limited to them. That is, it is to be understood that the configurations in which the structures that are not described in the claims are partially modified as appropriate also fall in the technical scope of the present invention, as long as the configurations include the structures described in the claims of the present application and the structures equivalent thereto.

The present invention can be preferably used in armatures for rotating electrical machines, which include an armature core in which a plurality of slots extending in the axial direction of a cylindrical core reference plane are arranged so as to be distributed in the circumferential direction of the core reference plane, and a coil that is wound about the armature core. 

1. An armature for a rotating electrical machine, comprising: an armature core in which a plurality of slots extending in an axial direction of a cylindrical core reference plane are arranged so as to be distributed in a circumferential direction of the core reference plane; and a coil that is wound about the armature core, wherein the coil is formed by using a plurality of segment conductors each including a conductor side portion placed in the slot, and a pair of protruding portions extending from the conductor side portion to protrude beyond the armature core to both sides in the axial direction, and tilted in the circumferential direction with respect to an extending direction of the conductor side portion so as to be located gradually away from the armature core in the axial direction, extending directions of the pair of protruding portions in the circumferential direction are opposite from each other, each of the protruding portions is joined to the protruding portion of another one of the segment conductors, which is a joint segment conductor to be joined to the each protruding portion, at least one of the two protruding portions to be joined together has a offset bent portion that offsets a tip end toward the other of the protruding portions in a radial direction of the core reference plane, and joint faces formed in the tip ends of the two protruding portions are joined together so as to face each other in the circumferential direction.
 2. The armature for the rotating electrical machine according to claim 1, wherein an adjacent same-layer segment conductor for each of the segment conductors is another one of the segment conductors whose conductor side portion is placed in a same position in the radial direction in an adjacent one of the slots, and the offset bent portion is provided in a gap in the circumferential direction between the tip end of the protruding portion to be joined that is included in the joint segment conductor, and the tip end of the protruding portion included in the adjacent same-layer segment conductor for the joint segment conductor.
 3. The armature for the rotating electrical machine according to claim 1, wherein an adjacent same-layer segment conductor for each of the segment conductors is another one of the segment conductors whose conductor side portion is placed in the same position in the radial direction in the adjacent one of the slots, and the protruding portions of each of the segment conductors are respectively placed adjacent to the protruding portions of the adjacent same-layer segment conductor so as to be arranged parallel to the protruding portions of the adjacent same-layer segment conductor, and arranged next to each other at a same position in the radial direction as the protruding portions of the adjacent same-layer segment conductor.
 4. The armature for the rotating electrical machine according to claim 1, wherein the joint segment conductor for each of the segment conductors is another one of the segment conductors whose conductor side portion is placed at a position in the radial direction adjacent to the conductor side portion of the segment conductor in one of the slots different from the slot in which the each segment conductor is placed.
 5. The armature for the rotating electrical machine according to claim 1, further comprising: a plurality of radial arrangement portions in which a plurality of joints, each of which is formed between the joint faces of the two protruding portions, are arranged next to each other in the radial direction, and the plurality of joints forming each of the radial arrangement portions are arranged at uniform intervals in the radial direction.
 6. The armature for the rotating electrical machine according to claim 1, wherein the slots have an opening on one side in the radial direction of the core reference plane, and a width of the opening in the circumferential direction is set to such a width that allows the conductor side portion to be inserted in the radial direction.
 7. The armature for the rotating electrical machine according to claim 1, wherein the tip end of each of the protruding portions is formed at a same position in the radial direction as the tip end of a joint protruding portion, which is the protruding portion to be joined to the each protruding portion, so as to extend parallel to an extending direction of the tip end of the joint protruding portion.
 8. The armature for the rotating electrical machine according to claim 1, wherein each of the protruding portions includes a main body portion that extends in the circumferential direction, and is formed in a linear shape extending in a direction tilted with respect to the extending direction of the conductor side portion as the core reference plane is viewed in the radial direction and in an arc shape parallel to the core reference plane as the core reference plane is viewed in the axial direction.
 9. The armature for the rotating electrical machine according to claim 2, wherein an adjacent same-layer segment conductor for each of the segment conductors is another one of the segment conductors whose conductor side portion is placed in the same position in the radial direction in the adjacent one of the slots, and the protruding portions of each of the segment conductors are respectively placed adjacent to the protruding portions of the adjacent same-layer segment conductor so as to be arranged parallel to the protruding portions of the adjacent same-layer segment conductor, and arranged next to each other at a same position in the radial direction as the protruding portions of the adjacent same-layer segment conductor.
 10. The armature for the rotating electrical machine according to claim 9, wherein the joint segment conductor for each of the segment conductors is another one of the segment conductors whose conductor side portion is placed at a position in the radial direction adjacent to the conductor side portion of the segment conductor in one of the slots different from the slot in which the each segment conductor is placed.
 11. The armature for the rotating electrical machine according to claim 10, further comprising: a plurality of radial arrangement portions in which a plurality of joints, each of which is formed between the joint faces of the two protruding portions, are arranged next to each other in the radial direction, and the plurality of joints forming each of the radial arrangement portions are arranged at uniform intervals in the radial direction.
 12. The armature for the rotating electrical machine according to claim 11, wherein the slots have an opening on one side in the radial direction of the core reference plane, and a width of the opening in the circumferential direction is set to such a width that allows the conductor side portion to be inserted in the radial direction.
 13. The armature for the rotating electrical machine according to claim 12, wherein the tip end of each of the protruding portions is formed at a same position in the radial direction as the tip end of a joint protruding portion, which is the protruding portion to be joined to the each protruding portion, so as to extend parallel to an extending direction of the tip end of the joint protruding portion.
 14. The armature for the rotating electrical machine according to claim 13, wherein each of the protruding portions includes a main body portion that extends in the circumferential direction, and is formed in a linear shape extending in a direction tilted with respect to the extending direction of the conductor side portion as the core reference plane is viewed in the radial direction and in an arc shape parallel to the core reference plane as the core reference plane is viewed in the axial direction.
 15. The armature for the rotating electrical machine according to claim 2, wherein the joint segment conductor for each of the segment conductors is another one of the segment conductors whose conductor side portion is placed at a position in the radial direction adjacent to the conductor side portion of the segment conductor in one of the slots different from the slot in which the each segment conductor is placed.
 16. The armature for the rotating electrical machine according to claim 2, further comprising: a plurality of radial arrangement portions in which a plurality of joints, each of which is formed between the joint faces of the two protruding portions, are arranged next to each other in the radial direction, and the plurality of joints forming each of the radial arrangement portions are arranged at uniform intervals in the radial direction.
 17. The armature for the rotating electrical machine according to claim 2, wherein the slots have an opening on one side in the radial direction of the core reference plane, and a width of the opening in the circumferential direction is set to such a width that allows the conductor side portion to be inserted in the radial direction.
 18. The armature for the rotating electrical machine according to claim 3, wherein the joint segment conductor for each of the segment conductors is another one of the segment conductors whose conductor side portion is placed at a position in the radial direction adjacent to the conductor side portion of the segment conductor in one of the slots different from the slot in which the each segment conductor is placed.
 19. The armature for the rotating electrical machine according to claim 3, further comprising: a plurality of radial arrangement portions in which a plurality of joints, each of which is formed between the joint faces of the two protruding portions, are arranged next to each other in the radial direction, and the plurality of joints forming each of the radial arrangement portions are arranged at uniform intervals in the radial direction.
 20. The armature for the rotating electrical machine according to claim 3, wherein the slots have an opening on one side in the radial direction of the core reference plane, and a width of the opening in the circumferential direction is set to such a width that allows the conductor side portion to be inserted in the radial direction. 